Systems and methods employing a guidewire for positioning and stabilizing external instruments deployed within the body

ABSTRACT

Systems and methods for treating a tissue region employ an expandable structure projecting beyond the distal end of a catheter tube. A distal tail projects beyond the far end of the basket assembly. The distal tail includes a guidewire lumen that accommodates passage of a guidewire without threading the guidewire through the catheter tube.

RELATED APPLICATIONS

This application is a divisional application of co-pending U.S. patentapplication Ser. No. 10/017,906, filed Dec. 14, 2001, which claims thebenefit of the filing date of provisional U.S. Patent Application Ser.No. 60/278,738, filed Mar. 26, 2001, and entitled “Systems and Methodsfor Positioning and Stabilizing External Instruments Deployed within theBody.”

FIELD OF THE INVENTION

The invention generally relates to systems and methods for inserting andsecuring the position of an external instrument, such as a cathetertube, in the body, e.g., through the oral cavity and into the esophagusfor the treatment of gastric esophageal reflux disease (GERD).

BACKGROUND OF THE INVENTION

Procedures requiring insertion of an external instrument into the body,e.g., through the oral cavity into the esophagus, are known. Bite blocksare typically used to hole the patient's mouth open during theseprocedures. During these procedures, it also may be necessary to locatethe instrument in an intended position. It may also be necessary tostabilize the instrument in an intended position.

There remains a need for simple, cost-effective ways to introduce aninstrument through the oral cavity to locate the instrument and toselectively maintain the instrument in a fixed and stable positionduring a given medical procedure.

SUMMARY OF THE INVENTION

The invention provides systems and methods for treating a tissue region.The systems and methods employ an expandable structure that projectsbeyond the distal end of a catheter tube. A distal tail projects beyondthe far end of the basket assembly. The distal tail includes a guidewirelumen that accommodates passage of a guidewire without threading theguidewire through the catheter tube.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a-a/1 a-b is a side view of a bite block and five alternateembodiments of inserts carrying a centrally located gripping tool thatmay be employed with the bite block.

FIG. 1 b is a side view of a bite block and an embodiment of an insertcarrying an eccentrically located gripping tool that may be employedwith the bite block.

FIG. 1 c is a side view of a bite block and two alternate embodiments of“clip-on” inserts carrying eccentrically located gripping tools that maybe employed with the bite block.

FIG. 2 is a front view of a bite block incorporating an insert carryinga gripping tool with a cam mechanism.

FIG. 3 a is a schematic of a gripping tool showing the position of agripping element and actuator mechanism in a closed position.

FIG. 3 b is a schematic of a gripping tool showing the position of agripping element and actuator mechanism in an open position.

FIG. 4 a is a side view of one of the embodiments shown in FIG. 1 a-a.

FIGS. 4 b-4 d are front views illustrating the operation of the camsurfaces incorporated in the jaws of the insert shown in FIG. 4 a.

FIG. 4 e is a side view illustrating the open and closed positions ofthe jaws of the gripping tool shown in FIG. 4 a.

FIG. 5 a is a side view of an embodiment shown in FIG. 1 a-a thatincorporates a cam mechanism.

FIG. 5 b is an exploded view of FIG. 5 a.

FIG. 5 c is a front view of the insert shown in FIG. 5 a.

FIG. 5 d is a side view of the insert shown in FIG. 5 a, illustratingthe position of the cam mechanism in the open position.

FIG. 5 e is a front view of the insert shown in FIG. 5 a, illustratingthe position of the jaws of the gripping tool in the open position.

FIG. 5 f is a side view of the insert shown in FIG. 5 a, illustratingthe position of the jaws of the gripping tool in the open position.

FIG. 5 g is a side view of the insert shown in FIG. 5 a, illustratingthe position of the cam mechanism in the closed position.

FIG. 5 h is a front view of the insert shown in FIG. 5 a, illustratingthe position of the jaws of the gripping tool in the closed position.

FIG. 5 i is a side view of the insert shown in FIG. 5 a, illustratingthe position of the jaws of the gripping tool in the open position.

FIG. 6 a is a side view of an embodiment shown in FIG. 1 a-a thatincorporates a C-clamp mechanism.

FIG. 6 b is an exploded view of FIG. 6 a.

FIG. 6 c is a front view of the insert shown in FIG. 6 a.

FIG. 6 d is a front view of the insert shown in FIG. 6 a, illustratingthe position of the jaws of the gripping tool in the closed position.

FIG. 6 e is a front view of the insert shown in FIG. 6 a, illustratingthe use of the C-clamp and the position of the jaws of the gripping toolin the open position.

FIG. 7 a is a side view of an embodiment shown in FIG. 1 a-b thatincorporates a prong-clamp mechanism.

FIG. 7 b is a breakaway view of FIG. 7 a.

FIG. 7 c is a front view of the insert shown in FIG. 7 a.

FIG. 7 d is a front view of the insert shown in FIG. 7 a, illustratingthe position of the jaws of the gripping tool in the closed position.

FIG. 7 e is a front view of the insert shown in FIG. 7 a, illustratingthe use of the prong clamp and the position of the jaws of the grippingtool in the open position.

FIG. 8 a is a side view of an embodiment shown in FIGS. 1 a-b thatincorporates a clothespin-clamp mechanism centrally located within theinsert opening.

FIG. 8 b is a front view of the insert shown in FIG. 8 a.

FIG. 8 c is a front view of the insert shown in FIG. 8 a, illustratingthe position of the jaws of the gripping tool in the closed position.

FIGS. 8 d-8 f are front views illustrating the insertion of an externalinstrument into a bite block utilizing the upturned edges incorporatedin the jaws of the insert shown in FIG. 8 a.

FIG. 8 g is a front view of the insert shown in FIG. 8 a, illustratingthe use of the clothespin-clamp and the position of the jaws of thegripping tool in the open position.

FIG. 9 a is a side view of an embodiment shown in FIG. 1 b thatincorporates a clothespin-clamp mechanism eccentrically located withinthe insert opening.

FIG. 9 b is a front view of the insert shown in FIG. 9 a.

FIG. 10 a is a side view of a bite block and an embodiment of aclip-type insert shown in FIG. 1 c that may be employed with the biteblock.

FIG. 10 b is a rear view of the insert shown in FIG. 10 a.

FIG. 10 c is a front view of a bite block incorporating the insert shownin FIG. 10 a.

FIG. 10 d is rear view of the bite block and incorporated insert shownin FIG. 10 c.

FIG. 11 a is a side view of a bite block and an embodiment of aclip-type insert shown in FIG. 1 c that may be employed with the biteblock.

FIG. 11 b is a rear view of the insert shown in FIG. 11 a.

FIG. 11 c is a front view of a bite block incorporating the insert shownin FIG. 11 a.

FIG. 11 d is rear view of the bite block and incorporated insert shownin FIG. 11 c.

FIG. 12 is a front view of a bite block, showing the insertion of anexternal instrument through the opening of the bite block alongside ajaw assembly and illustrating the movement required to position theexternal instrument in the jaw assembly.

FIG. 13 is a front view of a bite block as in FIG. 12, illustrating thepositioning of the external instrument in the jaw assembly.

FIG. 14 a is a side view of a catheter commonly employed in thetreatment of GERD, illustrating an expandable structure in a deflatedposition and a series of electrodes retracted.

FIG. 14 b is a side view of the catheter shown in FIG. 14 a,illustrating the expandable structure inflated and the series ofelectrodes extended.

FIG. 15 a is an enlarged side view of the distal tail of the expandablestructure shown in FIGS. 14 a and 14 b.

FIG. 15 b is a cutaway side view of the distal tail shown in FIG. 15 a,detailing the interior lumen within the tail.

FIG. 16 a is a side view of a guidewire being threaded through thedistal tail.

FIG. 16 b is a cutaway view of the distal tail illustrating thethreading of a guidewire through the interior lumen within the tail.

FIG. 17 is a side view of an individual in a reclined position with abite block carrying a gripping tool inserted in the individual's mouth.

FIG. 18 is a side view of the employment of a guidewire through a biteblock carrying a gripping tool and into the esophagus.

FIG. 19 is a side view of the employment of an endoscope through thebite block carrying a gripping tool and into the esophagus.

FIG. 20 is a side view illustrating the threading of an employedguidewire through a catheter tip.

FIG. 21 a is a side view illustrating the final positions of theguidewire and the catheter after employment.

FIG. 21 b is an enlarged side view of the lower esophagus and stomachshowing the final positions of the guidewire and the catheter afteremployment.

FIG. 22 is a side view of the jaws of the gripping tool being moved to aclosed position by manipulation of a cam mechanism.

FIG. 23 is a side view illustrating the employed catheter with theexpandable structure in an inflated position.

FIG. 24 is a side view illustrating the employed catheter with theexpandable structure inflated and the electrodes in an extendedposition.

FIG. 25 is a side view of the jaws of the gripping tool being moved toan open position by manipulation of a cam mechanism, with the expandablestructure deflated and the electrodes retracted.

FIG. 26 is a side view of the employed catheter being rotated axially,with the expandable structure deflated and the electrodes retracted.

FIG. 27 a is a schematic of a lesion pattern after one ablation sequenceis completed.

FIG. 27 b is a schematic of a lesion pattern after a second ablationsequence is performed following a 45° rotation of the catheter.

FIG. 28 is a side view of the employed catheter being advanced axially,with the expandable structure deflated and the electrodes retracted.

FIG. 29 is a schematic of a lesion pattern after two ablation sequencesseparated by 45° are performed at each of four levels.

FIG. 30 is a side view showing the positioning of a catheter within thecardia of the stomach.

FIG. 31 a is a schematic of a lesion pattern after one ablationsequence.

FIG. 31 b is a schematic of a lesion pattern after a second ablationsequence is performed following a 22.5° rotation of the catheter.

FIG. 31 c is a schematic of a lesion pattern after a third ablationsequence is performed following a 22° rotation of the catheter in theopposite direction.

FIG. 32 is a schematic of a lesion pattern after three ablationsequences separated by 22.5° are performed at each of two levels.

FIG. 33 is a side view of a catheter commonly employed in the treatmentof GERD, illustrating an expandable structure comprising an array oftubular spines, one of which accommodates passage of a guidewire.

FIG. 34 is a cross-section view of one of the spines of the expandablestructure illustrated in FIG. 33, detailing the interior of the threelumens that make up the spine.

FIG. 35 is a schematic of the exterior surface of a section of the spineshown in FIG. 34, illustrating the positioning of openings within thelumens and electrode and temperature sensing elements carried within thelumens.

FIG. 36 a shows an exterior surface of the spine of the expandablestructure illustrated in FIG. 33 that accommodates passage of aguidewire.

FIG. 36 b illustrates the interior surface of the spine shown in FIG. 36a.

FIG. 37 is an exploded view of the expandable structure carried at thedistal region of the catheter shown in FIG. 33, illustrating theguidewire lumen carried by a spine and a two-piece distal guideassembly.

FIG. 38 is a cross-section view of the inner sheath taken generallyalong line 38-38 in FIG. 37.

FIG. 39 is a partially assembled side view of the expandable structureshown in FIG. 37, illustrating the attachment of the inner sheath andthe coupling of an expandable body to the inner sheath.

FIG. 40 is a fully assembled side view of the expandable structure shownin FIG. 39, illustrating the placement of the outer and inner sheath ofthe guide assembly and depicting a guidewire thread through the distalguide assembly and guidewire lumen.

DESCRIPTION OF THE PREFERRED EMBODIMENT

I. The Bite Block

FIGS. 1 a-a/1 a-b shows a bite block 10. A bite block 10 is commonlyused to hold an individual's mouth open during insertion of aninstrument into the oral cavity. For example (see FIG. 21 a), a biteblock 10 can be utilized during procedures requiring insertion of acatheter tube 19 through the oral cavity into the esophagus 84, such asin the treatment of gastroesophageal reflux disease (GERD).

The bite block 10 may be conventional, formed, e.g., from hard, medicalgrade plastic by conventional molding techniques.

Conventional bite blocks 10 comprise an opening 11 for insertion of anexternal instrument 15 (as shown in phantom lines in FIG. 1 a).Typically, the opening 11 is large enough to readily accommodateinsertion of a variety of differently sized and shaped instruments andis therefore not capable of holding an instrument in a fixed orstabilized position.

As a result, insertion of an instrument 15 through the bite block 10does not automatically result in the instrument 15 being held in theproper position. Correct positioning of the instrument 15 is generallyuseful to effective performance of a procedure.

It is therefore necessary for an individual performing a procedure (oran assistant) to hold the instrument 15 in the proper position, oftenfor extended periods of time. This can be both cumbersome and difficultto do.

One aspect of the invention provides for a gripping tool (T) forassociation with a bite block 10. Eight embodiments of a gripping tool(T1-T8) are shown in FIGS. 1 a-a/1 a-b, 1 b, and 1 c. Five of theembodiments (T1-T5) are shown in FIG. 1 a-a/1 a-b. Another embodiment(T6) is shown in FIG. 1 b. Two additional embodiments (T7 and T8) areshown in FIG. 1 c.

The gripping tool (T) holds an instrument 15 in a fixed or stabilizedposition within the oral cavity during a procedure and permits removalof the instrument upon completion of the procedure, as will be describedin greater detail later. It further permits the moving of the instrument15 from one fixed position to an alternate fixed position, as will alsobe described in greater detail later.

Thus, the invention permits the hands of the provider to be freed duringthe procedure and assures that the instrument 15 will not inadvertentlybe moved during the procedure.

The gripping tool (T) or any portion of it may be integral with the bodyof the bite block 10. Alternately, the gripping tool (T) or any portionof it may be part of an insert 12 that is selectively attachable withinthe opening 11 of the bite block 10 at the instant of use.

FIGS. 1 a-a/1 a-b, 1 b, and 1 c show eight representative embodiments ofgripping tools, T1 to T8, each taking the form of an insert 12insertable into the bite block opening 11. FIG. 2 shows a bite block 10carrying one embodiment of the gripping tool (T2) after insertion intothe bite block 10.

In any one of the embodiments of the gripping tool, T1 to T8 shown inFIGS. 1 a-a/1 a-b, 1 b, and 1 c, the inserts 12 may be formed, e.g.,from hard, medical grade plastic by conventional molding techniques.

In the illustrated embodiments T1-T6, the insert 12 is a generallycylindrical hollow body constructed to couple to the bite block 10 uponinsertion. As shown in FIGS. 1 a-a/1 a-b and 1 b, in the illustratedembodiments T1-T6, the insert 12 comprises at least three features thatserve to secure and guide the insert into the proper position within thebite block opening 11.

First, as shown in FIGS. 1 a-a/1 a-b, the insert 12 includes a top vane14 and a bottom vane 23 that extend the length of the insert 12. Thevanes 14 and 23 are tapered so as to secure the insert 12 in properposition within the bite block 10 by making friction fit engagementagainst the interior wall of the bite block opening 11.

Alternately, as shown in FIG. 1 b, a second top vane 14 and a secondbottom vane 23 may be provided.

Second, the insert 12 includes a stoprest 13 to prevent over insertionof the gripping tool (T). The stoprest 13 is a straight perpendicularextension of the front edge of any of the vanes 14 or 23.

In the embodiments T1 to T5 shown in FIG. 1 a-a/1 a-b, the stoprest 13is located on the top vane 14. In the embodiment T6 shown in FIG. 1 b,the stoprests 13 are located on both top vanes 14 and bottom vanes 23.

Of course, any number of vanes 14 and 23 and stoprests 13 can beprovided.

Third, to further secure the insert 12 properly within the bite blockopening 11, the insert 12 also includes first and second lips 16 onopposing sides of the insert 12. The lips 16 have a plastic memory so asto engage the rear edge of the bite block 10 in a snap fit when theinsert 12 is properly positioned within the bite block opening 11.

In alternate embodiments T7 and T8 (see FIG. 1 c), an alternate insert12′ is provided that incorporates a “clip-on” type mechanism constructedto couple to the bite block 10 upon insertion. FIGS. 10 c-10 dillustrate a bite block 10 carrying one embodiment (T7) of the clip-oninsert 12′ after insertion into the bite block 10.

FIGS. 11 c and 11 d illustrate a bite block 10 carrying anotherembodiment (T8) of the clip-on insert 12′ after insertion into the biteblock 10.

In the illustrated embodiments T7-T8, as shown in FIGS. 10 a-10 d and 11a-11 d, the insert 12′ comprises at least three features that serve tosecure and guide the insert 12′ into the proper position within the biteblock opening 11.

First, as shown in FIGS. 11 a and 11 b, the insert 12′ is a memberhaving a “folded” or “curved” shape whereby the insert 12′ is adapted toslide over the wall of the bite block 10 on either the right or leftside of the opening 11. In this arrangement, the “fold” or curve”results in the insert 12′ having a first side 94 and a second side 96.

The first side 94 of the insert 12′ is adapted to be positioned in theinterior of the opening 11 and rest against the bite block 10 wall whenthe insert 12′ is positioned within the bite block 10 (see FIGS. 11 cand 11 d). The first side 94 carries a jaw assembly 18. The second side96 is adapted to be positioned exterior to opening 11 and rest againstthe bite block 10 wall when the insert 12 is positioned within the biteblock 10.

Second, the insert 12′ is curved to prevent rotation within the biteblock 10. In the embodiments illustrated in FIGS. 10 a-10 d and 11 a-11d, the opening 11 is generally oval shaped. The insert 12′ is shaped soas to match the curvature of the bite block 10 on the right or left sideof the bite block 10, but not necessarily the top or bottom of the biteblock 10.

This arrangement results in the gripping tool (T) having an eccentriclocation (see FIGS. 10 c and 11 c). The eccentric location provides alarger area in which to insert the external instrument 15 beforepositioning it within the gripping tool (T). The insertion of anexternal instrument 15 within a bite block 10 carrying an eccentricallylocated gripping tool (T) is illustrated in FIGS. 12 and 13.

As shown in FIG. 12, an external instrument 15 is inserted within thebite block opening 11. As indicated by arrows in FIG. 12, the externalinstrument 15 can then moved laterally to position it within thegripping tool (T).

FIG. 13 illustrates the external instrument 15 positioned within thegripping tool (T).

Third, the insert 12′ contains opposed grasping clasps positioned onopposite interior and exterior sides of the bite block 10 wall. Ofcourse, the construction and number of grasping clasps can vary.

In the embodiment illustrated in FIGS. 10 a and 10 b, two outer graspingclasps 98 are spaced parallel to each other and positioned to be on oneside of the bite block 10 wall when the insert 12′ is positioned withinthe bite block 10. An inner clasp 100 is positioned (desirablyequidistant) between the outer clasps 98 and positioned to be on theopposite side of the bite block 10 wall from the outer clasps 98 whenthe insert 12′ is positioned within the bite block 10.

Each of the clasps 98 and 100 has a foot-like appendage 102 extendingperpendicularly from the end of the clasps 98 and 100. The foot-likeappendages 102 are capable of abutting against the back wall of biteblock 10 when the insert 12′ is positioned within the bite block 10,such that they provide a snap fit when the insert 12′ is positionedwithin the bite block 10.

Regardless of the particular structure, the purposes of the grippingtool (T) are to accommodate passage of an external instrument 15 throughthe bite block 10 and to grip the external instrument 15.

To this end, as illustrated in FIGS. 3 a and 3 b, the gripping tool (T)comprises gripping elements 17 that are selectively movable and capableof pivoting between an open position (P1) (see FIG. 3 b) and a closedposition (P2) (see FIG. 3 a), such that the distance between theelements 17 is greater in P1 than in P2. An actuator mechanism 21effectuates movement of the elements between P1 and P2.

P1 (shown in FIG. 3 b) is an open spaced-apart position corresponding toa first distance (D1) between the gripping elements 17. P2 (shown inFIG. 3 a) is a closed adjacently-spaced position corresponding to asecond distance (D2) between the gripping elements 17, such that D2 isless than D1.

As FIG. 3 b shows, in P1 the gripping tool (T) accommodates passage ofan external instrument 15 through the bite block 10. As FIG. 3 a shows,in P2 the gripping tool (T) contacts the periphery of the externalinstrument 15, thereby maintaining the instrument 15 in a fixed positionwithin the bite block 10.

As FIGS. 1 a-a/1 a-b, 1 b, and 1 c demonstrate, and as has alreadygenerally been discussed, the gripping tool (T) may take a variety ofembodiments, eight of which (T1 to T8) are shown in FIGS. 1 a-a/1 a-b, 1b, and 1 c. Other embodiments, of course, are possible.

A. Bite Block Embodiment T1

FIGS. 4 a-4 e detail one of the embodiments (T1) shown in FIG. 1 a andits use. In the embodiment illustrated in FIG. 4 a, the gripping element17 consists of a jaw assembly 18 carried by the insert 12. The jawassembly 18 comprises a first jaw 40 and a second jaw 42. The jaws 40and 42 extend from the insert 12 at parallel and oppositely spacedlocations, thus having interior facing surfaces and exterior non-facingsurfaces relative to each other.

In the illustrated embodiment, resilient plastic memory biases the jaws40 and 42 toward the closed position P2. The relative positions of thejaws 40 and 42 in P1 (phantom lines) and P2 (solid lines) areillustrated in FIG. 4 e.

As shown in FIGS. 4 a-4 d, each of the jaws 40 and 42 includes a firstindented cam surface 20 and a pair of second raised cam surfaces 22 oneach jaw 40 and 42 flanking the indented cam surface 20.

The first cam surface 20 comprises an area of reduced thickness in thewall of the jaws 40 and 42. The first cam surfaces 20 are normallyoppositely spaced at the second distance D2, as FIG. 4 d shows, tonormally grip the instrument 15 confined between the jaws 40 and 42,corresponding to position P2.

The second cam surfaces 22 comprise areas of greater thickness in thewalls of the jaws 40 and 42.

As FIG. 4 c shows, manipulation of an external instrument 15 between anopposing pair of second cam surfaces 22 causes the jaws 40 and 42 toyield and open. The first cam surfaces 20 are moved to the firstdistance D1, corresponding to position P1, thereby allowing the externalinstrument 15 to be inserted between the jaws 40 and 42 and removed fromthe jaws 40 and 42.

In this embodiment, the jaws 40 and 42 are formed to include theresilient plastic memory that, together with the cam surfaces 20 and 22,provides the actuator mechanism 21 for the jaws 40 and 42. Thecombination of the plastic memory and the cam surfaces 20 and 22 enablesthe jaws 40 and 42 to be moved so as to pivot selectively between P1 andP2.

More particularly, the resilient plastic memory yields in response tocontact between the instrument 15 and the second cam surfaces 22 toallow the external instrument 15 to be inserted between the jaws 40 and42 (position P1 to P2) and, likewise, to be removed from the jaws 40 and42 (position P2 to P1).

In the closed position, the jaws 40 and 42 are capable of holding anexternal instrument 15 in a fixed position. In the open position, thejaws 40 and 42 are positioned such that the external instrument 15 isnot held in a fixed position, allowing it to be inserted or removed.

In the illustrated embodiment, the jaws 40 and 42 are carried by aninsert 12. Alternately, the jaws 40 and 42 may be integral with a biteblock 10.

B. Bite Block Embodiment T2

FIGS. 5 a-5 i detail a second embodiment (T2) of the gripping tool shownin FIG. 1 a and its use. In the embodiment illustrated in FIG. 5 a, thegripping element 17 consists of a jaw assembly 18. The jaw assembly 18comprises a first jaw 40 and a second jaw 42 carried by the insert 12.The jaws 40 and 42 are similar to the jaws 40 and 42 in FIGS. 4 a-4 e,but need not contain first cam surfaces 20 or second cam surfaces 22.

In this embodiment, the actuator mechanism 21 includes a resilientplastic memory in the jaws 40 and 42 and a cam mechanism 24 coupled tothe jaws 40 and 42. In the illustrated embodiment, this resilient memorybiases the jaws 40 and 42 toward the P1, or open position shown in FIGS.5 d-5 f. Engagement of a series of cam regions on the control knob 26 bymanipulation of the cam mechanism 24 overcomes this bias and moves thejaws 40 and 42 from the open (P1) position to the closed (P2) position,shown in FIGS. 5 g-5 i.

Alternately, the resilient memory can bias the jaws 40 and 42 in the P2,or closed, position. In yet another alternate embodiment, the jaws 40and 42 need not be biased in either position.

A variety of cam mechanisms 24 can be utilized. The cam mechanism 24 canbe conventional, formed, e.g., from hard, medical grade plastic byconventional molding techniques.

FIG. 5 b illustrates an embodiment in which the cam mechanism 24includes a control knob 26 and a pair of control appendages 28. As FIG.5 a shows, the control appendages 28 are connected to the jaws 40 and 42and engage the control knob 26. The control knob 26 rotates on theappendages 28.

Each jaw 40 and 42 includes a control appendage 28 that extends from therespective jaw 40 or 42 in a perpendicular direction, as bestillustrated in FIGS. 5 b-5 c. Rotation of the control knob 26 exertsforce on the control appendages 28 and thereby opens and closes the jaws40 and 42 (i.e., moves the jaws 40 and 42 selectively between P1 andP2).

In the illustrated embodiment (see FIG. 5 b), the control knob 26 takesa ring form having an interior surface and an exterior surface. Theinterior surface includes a pair of diametrically opposed first camregions 30. A pair of diametrically opposed second cam regions 32 areoppositely spaced in the interior surface at a decreased diameterrelative to the first cam regions 30.

The control appendages 28 rest within the interior surface of thecontrol knob 26 in contact with either the first cam regions 30 or thesecond cam regions 32. Rotation of the control knob 26 in a firstdirection (counterclockwise as shown by arrow in FIG. 5 d), brings thefirst cam regions 30 into contact with the appendages 28.

When the appendages 28 rest in contact with the first cam regions 30,the jaws 40 and 42 assume their normally biased open spaced-apartposition (P1), corresponding to a first distance (D1) between the jaws40 and 42. The position of the cam in the P1 position is shown in FIG. 5d. The corresponding positioning of the jaws 40 and 42 in the P1position is shown in FIGS. 5 e-5 f.

In the open position (see FIGS. 5 e and 5 f), the jaws 40 and 42 arepositioned such that the external instrument 15 is not held in a fixedposition, allowing it to be inserted or removed.

Rotation of the control knob 26 in a second direction (clockwise asshown by arrow in FIG. 5 g) brings the second cam regions 32 intocontact with the appendages 28.

When the control appendages 28 rest in contact with the second camregions 32, the jaws 40 and 42 are moved against the biasing force intothe closed adjacently-spaced position (P2), corresponding to a seconddistance (D2) between the jaws 40 and 42, such that D2 is less than D1.The position of the cam in the P2 position is shown in FIG. 5 g. Thecorresponding positioning of the jaws 40 and 42 in the P2 position isshown in FIGS. 5 h-5 i.

In the closed position (see FIGS. 5 h and 5 i), the jaws 40 and 42 arecapable of holding an external instrument 15 in a fixed position.

As best illustrated in FIG. 5 b, the control knob 26 desirably includesfirst and second grasping extensions 34 to aid in the rotation of thecontrol knob 26 circumferentially upon the appendages 28.

A first and second stopguard 36 (see FIG. 5 b) are also desirablyprovided. The stopguards 36 prevent over-rotation of the control knob 26in the first and second directions.

Rotation thus permits the control knob 26 to move selectively betweenP1, in which the control appendages 28 contact the first cam regions 30,and P2, in which the control appendages 28 contact the second camregions 32, thus permitting the jaws 40 and 42 to pivot between the D1and D2 positions. In P2, the first stopguard 36 rests against the firstcontrol appendage 28 and the second stopguard 36 rests against thesecond control appendage 28.

In P1, the first stopguard 36 does not contact the first controlappendage 28 and the second stopguard 36 does not contact the secondcontrol appendage 28. However, further rotation in the first directionbeyond P1 is prevented by contact between the stopguards 36 and theiropposing control appendage 28.

In the illustrated embodiment, the cam mechanism 24 and jaws 40 and 42are carried by an insert 12 for a bite block 10. Alternately, the cammechanism 24, the jaws 40 and 42, or both may be integral with the biteblock 10.

C. Bite Block Embodiment T3

FIGS. 6 a-6 e detail another embodiment (T3) shown in FIG. 1 a and itsuse. In the embodiment illustrated in FIG. 6 a, the gripping element 17takes the form of jaw assembly 18 comprising a “C-clamp” 38 carried bythe insert 12.

As FIGS. 6 a-6 c best show, this C-clamp 38 includes levers comprising afirst jaw 40′, a second jaw 42′, and a third jaw 44. The jaws 40′, 42′,and 44 each include a first region 45 and second region 47.

The first region 45 is generally semi-circle-shaped. The second region47 is a straight appendage extending from the end of the first region 45and serves as a grasping appendage.

The third jaw 44 is a mirror image of the first jaw 40′ and the secondjaw 42′ also having a first region 45 and a second region 47.

As shown in FIG. 6 b, the C-clamp 38 also comprises a post 94 extendingfrom the top of the front surface of the insert 12. The post 94 extendsthrough corresponding points on the first region 45 of each jaw 40′,42′, and 44. Thus, the post 94 serves as an axis upon which the jaws40′, 42′, and 44 are attached in a hinged fashion such that they maypivot selectively along the axis of the post 94.

The first jaw 40′ is positioned proximal to the front surface of theinsert 12 along the axis of the post 94. The third jaw 44 is positionedmedially along the axis of the post 94. The second jaw 42′ is positioneddistally along the axis of the post.

The hinged arrangement permits the jaws 40′, 42′, and 44 to pivotbetween a first position (P1) (see FIG. 6 e) and a second position (P2)(see FIG. 6 d).

In P1, the second region 47 of the third jaw 44 is aligned with thesecond regions 47 of the first jaw 40′ and the second jaw 42′. In thisposition, the three first regions 45 form an opening of a first diameter(D1). This corresponds to an open position, in which an externalinstrument 15 is not able to be held in a fixed position.

In P2, the second region 47 of the third jaw 44 is spaced apart from thesecond regions 47 of the first jaw 40′ and the second jaw 42′. In thisposition, the first regions 45 of the three jaws form an opening of asecond diameter (D2), such that D2 is less than D1. This corresponds toa closed position, in which an external instrument 15 can be held in afixed position.

The hinge mechanism provides a resilient plastic memory and serves as anactuator mechanism 21 that enables the jaws 40′, 42′, and 44 to be movedso as to pivot selectively between P1 and P2. This resilient memorybiases the jaws 40′, 42′, and 44 toward the closed position P2 (see FIG.6 d). Application of “squeezing” pressure (illustrated by arrows in FIG.6 e) on the second regions of the jaws 40′, 42′, and 44 overcomes thisbias and moves the jaws 40′, 42′, and 44 from the closed (P2) positionto the open (P1) position.

The C-clamp 38 may be conventional, formed, e.g., from hard, medicalgrade plastic by conventional molding techniques.

In the illustrated embodiment, the C-clamp 38 is carried by an insert 12for a bite block 10. Alternately, the C-clamp 38 or any portion of itmay be integral with the bite block 10.

D. Bite Block Embodiment T4

FIGS. 7 a-7 e detail another embodiment (T4) shown in FIG. 1 a and itsuse. In the embodiment illustrated in FIG. 7 a, the gripping element 17takes the form of jaw assembly 18 comprising a “prong-clamp” carried bythe insert 12.

As FIGS. 7 a-7 c show, this prong-clamp 38 comprises a first jaw 40 anda second jaw 42. The jaws 40 and 42 are similar to the jaws 40 and 42 inFIGS. 4 a-4 e, but need not contain first cam surfaces 20 or second camsurfaces 22.

As shown in FIG. 7 a, this prong-clamp 46 also includes leverscomprising a first prong 52, a second prong 54, and a third prong 56.

As also shown in FIG. 7 a, the first prong 52 and second prong 54 areintegral with the first jaw 40. The prongs consist of a first section 48and a second section 50. The first section 48 extends perpendicularlyfrom the first jaw 40 at a right angle. The second section 50 extendsperpendicularly from the first section 48 at a right angle from thefirst section 48.

The first prong 52 and second prong 54 are spaced apart along the firstjaw 40 and positioned such that they are parallel to each other.

As shown in FIG. 7 b, the third prong 56 is integral with the second jaw42 and is spaced (desirably equidistant) between the first prong 52 andthe second prong 54. The third prong 56 consists of a first section 48and a second section 50 and is essentially a mirror image of the firstprong 52 and second prong 54.

That is, the first section 48 extends perpendicularly from the secondjaw 42 at a right angle. The second section 50 extends perpendicularlyfrom the first section 48 at a right angle from the first section 48 andserves as a grasping appendage.

The jaws 40 and 42 possess a resilient plastic memory that serves as anactuator mechanism 21 that enables the jaws 40 and 42 to be moved so asto pivot selectively between P1 and P2.

In the open (P1) position, illustrated in FIG. 7 e, the second section50 of the third prong 56 is aligned with the second sections 50 of thefirst prong and the second prong 54. In this position, the three prongsimpart a correspondingly spaced-apart relation to the jaws 40 and 42corresponding to a first diameter (D1). This corresponds to an openposition, in which an external instrument 15 is not able to be held in afixed position.

In P2, illustrated in FIG. 7 d, the second section 50 of the third prong56 is spaced apart from the second sections 50 of the first prong 52 andthe second prong 54. In this position, the three prongs impart acorrespondingly spaced-apart relation to the jaws 40 and 42corresponding to a second diameter (D2), such that D2 is less than D1.This corresponds to a closed position, in which an external instrument15 can be held in a fixed position.

The resilient plastic memory biases the jaws 40 and 42 toward theclosed, or P2 position. Application of “squeezing” pressure (illustratedby arrows in FIG. 7 e) on the second sections 50 of the prongs 52, 54,and 56 overcomes this bias and moves the jaws 40 and 42 from the closed(P2) position to the open (P1) position.

The prong clamp 46 may be conventional, formed, e.g., from hard, medicalgrade plastic by conventional molding techniques.

In the illustrated embodiment, the prong-clamp 46 and jaws 40 and 42 arecarried by an insert 12 for a bite block 10. Alternately, theprong-clamp 46 or any portion of it, the jaws 40 and 42, or anycombination thereof may be integral with the bite block 10.

E. Bite Block Embodiment T5

FIGS. 8 a-8 g detail another embodiment (T5) shown in FIG. 1 a and itsuse. In the embodiment illustrated in FIG. 8 a, the gripping element 17takes the form of a jaw assembly 18 comprising a “clothespin-type clamp”104 carried by the insert 12.

As illustrated in FIGS. 8 a-8 g, this clothespin-clamp 104 comprises aC-shaped groove 106. The top side of the groove 106 comprises a firstjaw 40 having an upturned edge 108. The bottom side of groove 106comprises a second jaw 42 having a downturned edge 110. The upturned enddownturned edges 108 and 110 serve as leading edges that guide theinsertion of an external instrument 15 into the groove 104.

As shown in FIGS. 8 a-8 g, this clothespin-clamp 104 also includes afirst arm 112 integral with and extending horizontally from the top ofthe C-shape and a second arm 114 integral with and extendinghorizontally from the bottom of the C-shape, positioned such that thefirst arm and second arms 112 and 114 are parallel to each other.

The jaws 40 and 42 possess a resilient plastic memory that, togetherwith the upturned and downturned edges 106 and 108 and the first andsecond arms 112, serve as an actuator mechanism 21 that enables the jaws40 and 42 to moved so as to pivot selectively between P1 and P2.

This resilient plastic memory biases the jaws 40 and 42 toward theclosed position P2 (shown in FIG. 8 c).

As illustrated in FIGS. 8 d-8 f, the resilient plastic memory yields inresponse to contact between the instrument 15 and the edges 108 and 110to move the jaws 40 and 42 from the closed (P2) position to the open(P1) position.

As illustrated in FIG. 8 g, application of “squeezing” pressuresimultaneously on the first and second arms 112 and 114 (illustrated byarrows in FIG. 8 g) also serves to overcome the bias and move the jaws40 and 42 from the closed (P2) position to the open (P1) position.

In P1, the jaws 40 and 42 assume an open spaced-apart positioncorresponding to a first diameter (D1) between the jaws 40 and 42. Thiscorresponds to an open position, illustrated in FIGS. 8 d and 8 g, inwhich an external instrument 15 is not able to be held in a fixedposition.

In P2, the jaws 40 and 42 assume their normally biased closedadjacently-spaced position corresponding to a second diameter (D2), suchthat D2 is less than D1. This corresponds to a closed position, bestillustrated in FIG. 8 f, in which the jaws 40 and 42 are capable ofholding an external instrument 15 in a fixed position.

The clothespin-clamp 104 may be conventional, formed, e.g., from hard,medical grade plastic by conventional molding techniques.

In the illustrated embodiment, the clothespin-clamp 104 is carried by aninsert 12 for a bite block 10. Alternately, the clothespin-clamp 104 orany portion of it may be integral with the bite block 10.

F. Bite Block Embodiment T6

FIGS. 9 a and 9 b detail another embodiment (T6) shown in FIG. 1 b andits use. This embodiment is similar to embodiment T5, except that thejaw assembly 18 is adapted to be eccentrically located within the biteblock opening 11 when the insert 12 is positioned within the bite block10.

In the embodiments illustrated in T1-T5, the jaw assembly 18 is adaptedso as to be centrally located within the bite block opening 11 when theinsert 12 is positioned within the bite block 10.

Alternately, the jaw assembly 18 in any of the embodiments T1-T5 can bepositioned so as to be eccentric, as in embodiment T6. As previouslynoted, an eccentric location provides for a larger area in which toinsert the external instrument 15 before positioning it within thegripping tool (T).

G. Bite Block Embodiment T7

FIGS. 10 a-10 d detail another embodiment (T7) shown in FIG. 1 c and itsuse.

The embodiment illustrated in FIG. 10 a provides a C-shaped groove 106functionally and structurally similar to that contained in embodimentT6. However, rather than a generally cylindrical hollow body insert 12,the C-shaped groove 106 is carried by a clip-on insert 12′ as previouslydescribed. In this arrangement, the first and second arms 112 and 114are not provided.

As best shown in FIGS. 10 b and 10 d, the first side 94 of the insert12′ includes the C-shaped groove 106. The groove 106 extendsperpendicularly from the third clasp 100.

The groove 106 may be coated with an elastomeric material, making thegroove 106 more tacky, thereby aiding in grasping an externalinstrument. This coating can be accomplished by either placing a tubeover the groove 106 or placing a low durameter pad over the groove 106.

As best seen in FIGS. 10 a and 10 c, the second side 96 of the insert12′ includes the first and second clasps 98. In this arrangement, thefirst and second clasps 98 are positioned exterior to the opening 11along the bite block 10 wall when the insert 12′ is positioned withinthe bite block 10. The third clasp 100 and groove 106 are positionedinterior to the opening 11 along the bite block 10 wall when the insert12′ is positioned within the bite block 10.

In the illustrated embodiment, the groove 106 is adapted to bepositioned eccentrically within the opening 11 when the insert 12′ ispositioned within the bite block 10. Alternately, the insert 12′ can beformed such that the groove 106 is positioned centrally within theopening 11 (not shown).

In the closed position (see FIG. 8 c), the groove 106 is capable ofholding an external instrument 15 in a fixed position. In the openposition (see FIG. 8 e), the groove 106 is positioned such that theexternal instrument 15 is not held in a fixed position, allowing it tobe inserted or removed.

The C-shaped groove 106 may be conventional, formed, e.g., from hard,medical grade plastic by conventional molding techniques.

In the illustrated embodiment, the C-shaped groove 106 is carried by aninsert 12′ for a bite block 10. Alternately, the C-shaped groove 106 orany portion of it may be integral with the bite block 10.

H. Bite Block Embodiment T8

FIGS. 11 a-11 d detail another embodiment (T8) shown in FIG. 1 c and itsuse.

The embodiment illustrated in FIG. 11 a provides a C-shaped groove 106mechanism on a clip-on type insert 12′ as in embodiment T7.

As best illustrated in FIGS. 11 b and 11 d, the first side 94 of theinsert 12′ includes the C-shaped groove 106 as described for embodimentT7. However, the groove 106 extends perpendicularly from the first andsecond clasps 98 rather than from the third clasp 100.

As best illustrated in FIGS. 11 a and 11 c, the second side 96 of theinsert 12′ includes the third clasp 100. In this arrangement, the thirdclasp 100 is positioned exterior to the opening 11 along the bite block10 wall when the insert 12′ is positioned within the bite block 10. Thefirst and second clasps 98 and groove 106 are positioned interior to theopening 11 along the bite block 10 wall when the insert 12′ ispositioned within the bite block 10.

As in embodiment T7, the groove 106 can be coated with an elastomericmaterial. While the illustrated embodiment shows an eccentric location,the groove 106 can be adapted to be centrally located within the opening11 when the insert 11 is positioned within the bite block 10, aspreviously noted for embodiment T7.

II. Use of the Gripping Tool

Any one of the gripping tools (T1-T8) described can be used with acatheter 58 designed for the treatment of gastroesophageal refluxdisease (GERD). One possible embodiment of such a catheter is shown inFIGS. 14 a and 14 b.

In the illustrated embodiment, a catheter 58 carries a series ofelectrodes 60 that, in use, can be coupled to a source of radiofrequency energy to ohmically heat tissue and create a lesion in thetissue region, e.g., lower esophageal spinchter 90 (see FIG. 21 b) orcardia 92 (see FIG. 30) or both. It has been discovered that naturalhealing of the lesions tightens the targeted and adjoining tissue.

FIGS. 14 a and 14 b show a representative embodiment for the catheter58. Typically, the catheter 58 comprises a catheter tube 19 having adistal region and a proximal region. The proximal region includes ahandle 62 incorporating control mechanisms. The distal region carries anexpandable structure 64 (e.g., suitable for contacting the loweresophageal sphinchter 90 during performance of procedures for thetreatment of GERD, as shown in FIG. 21 b).

As also shown in FIGS. 14 a and 14 b, the expandable structure 64includes an array of tubular spines 66 that form a basket that iscapable of being selectively expanded and contracted. The expandablestructure 64 further comprises an expandable body 68 (e.g., balloon)within the basket.

The purpose of the expandable body 68 is to cause the basket to expandand contract within the esophagus 84. The expanded structure 64 servesto temporarily dilate the targeted tissue, thus removing some or all thefolds normally present in the mucosal surface.

FIG. 14 a shows the expandable structure 64 in the contracted orcollapsed position. FIG. 14 b shows the expandable structure 64 in theexpanded position.

The electrodes 60 are carried within the spines 66 and are similarlycapable of extension and retraction. The electrodes 60 are selectivelymovable between two positions. The first position is a retractedposition, illustrated in FIG. 14 a, in which they are withdrawn in aspine 66. The second position is an extended position, illustrated inFIG. 14 b, in which they extend outward from the spine 66 through a holein the spine 66.

The electrodes 60 can be biased with either an antegrade or retrogradebend. The electrodes 60 can also be arranged in bipolar pairs or in asingular, spaced-apart relation suitable for monopolar operation. In theillustrated embodiment, the electrodes 60 show an antegrade bend and amonopolar arrangement.

FIGS. 15 a and 15 b illustrate an embodiment in which the expandablestructure 64 includes a distal tail 72 adapted to accommodate aguidewire 70. The purpose of the guidewire 70 is to aid insertion andguidance of the expandable structure 64 and catheter 58 through the oralcavity to a desired position within the esophagus 84 (see FIG. 21 a).The configuration of the distal tail 72 eliminates the need to threadthe guidewire 70 through the expandable structure 64 and the entire bodyof the catheter 58.

In the illustrated embodiment, the distal tail 72 extends approximately3 inches (range=1 to 5 inches) beyond the distal end of the basket. Thedistal tail 72 may be conventional, formed, e.g., from semi-rigid,medical grade plastic (e.g., Pebax™, polyurethane, silicone,Santoprene™, or other flexible materials) by conventional moldingtechniques.

An interior lumen 74 extends through the distal tail 72. The interiorlumen 74 is a passage that it does not communicate with any other lumenor structure within the body of the catheter 58. The purpose of theinterior lumen 74 is strictly to permit passage of a guidewire 70. In analternate embodiment, this lumen 74 could communicate with irrigation oraspiration lumens (not shown).

This interior lumen 74 terminates at the distal end in an opening 76 inthe distal end of the tail 72. The interior lumen 74 terminates at theproximal end in an orifice 78 that penetrates the wall of the distaltail 72. In a representative embodiment, the orifice 78 is locatedapproximately midway along the distal tail 72, or about one and one-halfinches from the opening 76.

A slot 80 along the axis of the distal tail 72 is provided in the wallof distal tail 72. In a representative embodiment, the slot 80 extendsapproximately 1 1/2 inches. The purpose of the slot 80 is to aid inthreading a guidewire 70. The threading of a guidewire 70 through theslot 80 is illustrated in FIGS. 16 a and 16 b.

The orifice 78 is located at the distal end of the slot 80, such thatthe guidewire 70 is guided by the slot 80 as it is threaded through theorifice 78. The slot 80 does not penetrate the wall of the distal tail72, thus it communicates with the interior lumen 74 in the distal tail72 only through the orifice 78. The proximal end of the slot 80 taperstoward the exterior surface of the distal tail 72, thereby enabling itto guide the guidewire 70 as it is threaded through the distal tail 72.

In use, the patient lies awake in a reclined or semi-reclined position.A bite block 10, desirably carrying a gripping tool (T) as previouslydescribed (see, e.g., FIG. 1 a) is placed in the patient's mouth andproperly positioned, as illustrated in FIG. 17. The gripping elements 17are placed in the open (P1) position (as shown in FIG. 3 b).

The physician passes the small diameter guidewire 70 through thepatient's mouth and pharynx, and into the esophagus 84 to the targetedsite, as illustrated in FIG. 18.

The targeted site for treatment of GERD is typically the loweresophageal sphincter 90 (see FIG. 21 b) or the cardia 92 of the stomach(see FIG. 30), or both.

The physician preferably employs an endoscope 86 in conjunction with theguidewire 70 for viewing the targeted site. Use of an endoscope 86 isshown in FIG. 19. The endoscope 86 can be either separately employed ina side-by-side relationship with the guidewire 70, or the endoscope 86may be introduced over the guidewire 70 itself. FIG. 19 illustratesemployment of an endoscope 86 over a guidewire 70.

To aid in determining the position of the endoscope 86, the tubal bodyof the endoscope 86 includes measured markings 88 along its length. Themarkings 88 indicate the distance between a given location along thetubal body and the endoscope 86.

Relating the alignment of the markings 88 to the bite block 10, thephysician can gauge, in either relative or absolute terms, the distancebetween the patient's mouth and the endoscope 86 in the esophagus 84.When the physician visualizes the desired treatment site, e.g., loweresophageal sphincter 90 (see FIG. 21 b) or cardia 92 (see FIG. 30), withthe endoscope 86, the physician records the markings 88 that align withthe bite block 10 and removes the endoscope 86, leaving the guidewire 70behind.

In the illustrated embodiment, the catheter tube 19 includes measuredmarkings 88 along its length. The measured markings 88 indicate thedistance between a given location along the catheter tube 19 and anoperative element (e.g., electrodes 60). The markings 88 on the cathetertube 19 correspond in spacing and scale with the measured markings 88along the tubal body of the endoscope 86.

The free proximal end of the guidewire 70 is thread through the opening76 in the distal tail 72 of the expandable structure 64, such that theguidewire 70 exits the distal tail 72 through the orifice 78, asillustrated in FIG. 20.

The catheter 58 is then advanced along the guidewire 70 through thepatient's mouth and pharynx and to the desired position in the esophagus84, e.g., lower esophageal sphincter 90. The positioning of the catheter58 in the lower esophageal sphincter 90 is illustrated in FIGS. 21 a and21 b.

An ablation sequence is then performed. The sequence typically comprisesthe following steps. First, the gripping elements 17 of the grippingtool (T) are moved (represented by arrows in FIG. 22) to the closed (P2)position (shown in FIG. 3 a), thereby holding the catheter 58 fixed inthe desired position, as shown in FIG. 22.

Second, the expandable body 68 is expanded (e.g., sterile water or airis injected into a balloon through a port in the handle 62 of thecatheter 58, causing it to inflate). The expandable structure 64 isthereby also expanded. FIG. 23 shows the position of the expandable body68 after expansion.

Third, the electrodes 60 are extended (e.g., by operation of a push-pulllever on the handle 62 of the catheter 58), as illustrated in FIG. 24.

Fourth, radio frequency energy is applied for a desired period of time(e.g., radio frequency energy in the range of about 400 kHz to about 10mHz is applied for approximately 90 seconds).

If desired, cooling liquid can be introduced during the ablationsequence (e.g., each spine 66 can include an interior lumen with a portto convey a cooling liquid like sterile water into contact with themucosal surface of the targeted tissue site) (not shown).

Fifth, the electrodes 60 are retracted (e.g., by operation of apush-pull lever on the handle 62 of the catheter 58).

Sixth, the expandable structure 64 is deflated.

Finally, the elements 17 of the gripping tool (T) are moved to the open(P1) position (shown in FIG. 3 b), thereby enabling the repositioning orremoval of the catheter 58. The opening of the elements 17 isillustrated by arrows in FIG. 25.

To create greater lesion density in a given targeted tissue area, it isalso desirable to create a pattern of multiple lesions, e.g., in ringsalong the targeted treatment site.

For example, multiple lesions may be obtained by performing a series ofablation sequences in both the lower esophageal sphincter 90 (see FIG.21 b) and the cardia 92 (see FIG. 30). The physician typically performsa series of ablation sequences in the lower esophageal sphincter 90,followed by a series of ablation sequences in the cardia 92, or viceversa.

For example, a “rotational sequence” is first employed in the loweresophageal sphincter 90 (see FIG. 21 b). In this sequence, with theelements 17 in the open (P1) position, the catheter 58 is rotatedaxially a desired number of degrees from the first position, asillustrated by arrows in FIG. 26. The elements 17 of the gripping tool(T) are then moved to the closed (P2) position and a second ablationsequence is performed.

The pattern of lesions created by such a rotational sequence is shown inFIGS. 27 a-27 b. FIG. 27 a corresponds to the pattern resulting from theinitial ablation sequence. FIG. 27 b represents the lesion pattern afterone rotation and ablation sequence.

In the illustrated arrangement, the lesion pattern corresponds to fourelectrodes 60 spaced at 90 degree angles on the catheter 58 (see FIG. 27a). The rotation is of approximately 45 degrees, thereby creating afinal lesion pattern comprising a “ring” of eight equidistant lesions(see FIG. 27 b).

Of course, a variety of electrode and rotational arrangements may beemployed to produce a variety of different lesion patterns.

In addition to or in place of a rotational sequence, an “axial sequence”may be employed. This process is illustrated in FIGS. 28-29. In thissequence, with the elements 17 in an open position, the catheter 58 isadvanced axially within the lower esophageal sphincter 90 from the siteof the first ablation sequence, as illustrated by arrow in FIG. 28.

The elements 17 of the gripping tool (T) are moved to the closedposition and a second ablation sequence is then performed. If desired, arotational sequence is then performed as previously described.

The catheter 58 is then advanced axially from the site of the secondablation sequence and the process is repeated (not shown).

The catheter 58 is then advanced axially from the site of the thirdablation sequence and the process is repeated (not shown).

One possible pattern of lesions formed in the lower esophageal sphincter90 resulting from such a combination of axial and rotational sequencesis illustrated in FIG. 29.

FIG. 29 corresponds to the lesion pattern resulting from a rotationalablation sequence being performed at each of four different depthswithin the lower esophageal sphincter 90. Thus, eight lesions are formedat each of four depths, for a total of thirty-two lesions.

Of course, a variety of rotational and axial arrangements may beemployed to produce a variety of different lesion patterns.

It is desirable to also form a lesion pattern in the cardia 92 (see FIG.30) of the stomach in addition to or in place of the lesion patternformed in the lower esophageal sphincter 90 (see FIG. 21 b).

To this end, after completing the desired lesion pattern in the loweresophageal sphincter 90, the catheter 58 is advanced axially into thecardia 92. The positioning of the catheter within the cardia 92 isillustrated in FIG. 30.

A first ablation sequence is then performed. A rotational sequence isthen performed if desired. For example, the catheter is rotated adesired number of degrees and a second ablation sequence is performed.The catheter 58 is then rotated the same number of degrees from the siteof the first ablation sequence in the opposite direction and a finalablation sequence is performed.

The pattern of lesions created by such a rotational sequence is shown inFIGS. 31 a-31 c.

FIG. 31 a corresponds to the pattern resulting from the initial ablationsequence. FIG. 31 b represents the lesion pattern after the firstrotation and ablation sequence. FIG. 31 c represents the lesion patternafter the second rotation and ablation sequence

In the illustrated arrangement, the lesion pattern corresponds to fourelectrodes 60 spaced at 90 degrees angles on the catheter 58. Therotation is of approximately 22.5 degrees, thereby creating a finallesion pattern of twelve lesions.

It is desirable to create a ring of twelve lesions in the cardia 92rather than a ring of eight lesions as created in the lower esophagealsphincter 90 to cover the larger surface area of the cardia 92.

This sequence may be repeated at a second depth in the cardia 92. FIG.32 represents the final lesion pattern created after the sequence isrepeated at a second depth. The lesion pattern illustrated is that oftwelve lesions created at each two depths, for a total of twenty-fourlesions created in the cardia 92.

Of course, a variety of electrode and rotational arrangements may beemployed to produce a variety of different lesion patterns.

Upon completion of all desired ablation sequences, the physician assuresthat the electrodes 60 are retracted and the expandable body 68 iscontracted (e.g., air or water is withdrawn from the balloon by asyringe through a port on the handle 62 of the catheter 58) (not shown).

The elements 17 of the gripping tool (T) are then verified as being inthe open position, the catheter 58 and guidewire 70 are withdrawn, andthe bite block 10 is removed from the patient's mouth (not shown).

III. Alternative Use of Gripping Tool

Any one of the gripping tools (T1-T8) described can also be used with analternate embodiment of the previously described catheter 58. Thisalternate embodiment enables the threading of a guidewire 70 outside thebody of the catheter 58, through a guidewire lumen 116 within one of thespines 66 of the expandable structure 64.

As in the previously described embodiment, and as seen in FIG. 33, theexpandable structure 64 includes an array of spines 66 that form abasket that is capable of being selectively expanded and contracted. Ina representative embodiment, the expandable structure 64 comprises fourspines 66. Of course, the expandable structure 64 can include a greateror lesser number of spines 66.

As will be explained in greater detail later, the guidewire lumen 116passes through one of the spines 66 outside the catheter 58 and outsideexpandable body 68. The guidewire lumen 116 further extends beyond thedistal end of the expandable structure 64 through a distal guideassembly 133.

As FIG. 33 illustrates, each of the spines 66 through which theguidewire 70 does not pass, comprises three lumens, designated L1, L2,and L3 in FIG. 33 and subsequent FIGS. 34-40. An arrangement of lumensof this type is detailed in co-pending U.S. patent application Ser. No.09/955,915, filed Sep. 19, 2001, now U.S. Pat. No. 6,699,243, which isherein incorporated by reference.

As shown in FIG. 35, the first or center passage L1 carries a movable,elongated electrode element 118. The distal end of the electrode element118 comprises an electrode 60. The electrode element 118 has a retractedposition, in which the distal end of the electrode element 118 iscontained within the spine 66, and an extended position in which thedistal end of the electrode element 118 extends out from the spine 66and is capable of piercing tissue. FIG. 35 shows the distal end of theelectrode element 118 in an extended position. When extended, theelectrode 60 exits L1 through an electrode opening 120.

As also shown in FIG. 35, a third passage L3 along side the firstpassage L1 is coupled to tubing 123 that carries processing fluid from afluid delivery device. When desired, e.g., to cool tissue during aprocedure, fluid is passed through L3 and exits L3 through an irrigationopening 122. The irrigation opening 122 can be generally aligned withthe electrode opening 120 so that ablation and cooling occur in the samegeneral tissue region. Alternatively, the irrigation opening 122 can beproximal or distal to the electrode opening 120.

As further shown in FIG. 35, a second passage L2 along side the firstpassage L1 can carry a temperature sensing element 124, e.g., athermocouple assembly. In the illustrated embodiment, the thermocoupleassembly includes a thermocouple that extends into the L2 lumen and thatcarries a temperature sensing element 124. The temperature sensingelement 124 is exposed through a temperature sensor opening 126.Alternatively, it can extend through the opening 126 and be secured tothe spine 66 proximal or distal to the opening 126.

The temperature sensor opening 126 can be generally aligned with theelectrode opening 120 and irrigation opening 122 so that ablation,temperature sensing, and cooling occur generally in the same localizedtissue region. Alternatively, as above discussed, the openings 120, 122,and 126 can be arranged proximal or distal to each other.

As shown in FIGS. 36 a and 36 b, the spine 66 that carries the guidewire70 includes the first and third lumens L1 and L3, which serve to carry,respectively, the electrode 66 and processing fluid tube 123, aspreviously described. In this arrangement, the lumen L2 is desirablyadapted to serve as the guidewire lumen 116 for passage of a guidewire70, rather than for carrying a temperature sensing element 124.

The guidewire lumen 116 is desirably made of a material that is lessstiff than the material of the adjacent L1 and L3 lumens, e.g.,polyurethane, polyethelyne, Pebax™, Peeks™, or other suitable material.This assures that, with the guidewire 70 inserted, the stiffness of theguidewire lumen 116 will approximate the stiffness of the adjacent L1and L3 lumens. This assures that the expandable structure 64 issymmetrical upon expansion of the expandable body 68 within theexpandable structure 64.

FIG. 36 a shows an exterior surface (i.e., the surface of the spinefacing away from expandable body 68) of a section of the spine 66 thatcarries the guidewire lumen 116. FIG. 36 b shows an interior surface(i.e., the surface of the spine facing toward the expandable body 68) ofthe same section of a spine 66.

In this arrangement, as best shown in FIG. 36 b, the thermocouple of thetemperature sensing element 124 desirably extends along the interiorsurface of the spine between the L1 and L2 lumens. The temperaturesensing element 124 is passed through an opening 126 formed between thetwo lumens L1 and L2, so that it is exposed on the exterior surface ofthe spine for use. The temperature sensor opening 126 is desirablyaligned with the electrode opening 120 and irrigation opening 122 aspreviously described.

FIG. 40 illustrates a guidewire 70 threaded through the guidewire lumen116 and the guide assembly 133 (see FIG. 33 also). As illustrated inFIG. 37, the guidewire lumen 116 preferably extends both proximally anddistally beyond the adjacent L1 and L3 lumens. The guidewire lumen 116has a distal opening 128 located beyond the distal end of the expandablestructure 64. The opening 128 serves as an exit for a guidewire 70threaded through the guidewire lumen 116 into the guide assembly 113.

The guidewire lumen 116 also has a proximal opening 130 that extendsproximal of the proximal end of the expandable structure 64. As alsoshown in FIG. 37, the proximal opening 130 rests on the exterior of thecatheter tube 19, to provide for an unimpeded passage of the guidewire70.

The guidewire lumen 116 extends entirely outside the body of thecatheter tube 19 and entirely outside the expandable body 68. This pathprovides stability and support for the expandable structure 64 duringpassage over the guidewire 70. The passage of the guidewire 70 throughthe lumen 116 prevents the guidewire 70 from contacting and/or damagingadjacent functional items carried in the expandable structure 64. Forexample, contact between the guidewire 70 and the energy conductingelectrode is prevented, to thereby avoiding conduction of ablationenergy by or the heating of the guidewire 70. The passage of theguidewire 70 through the lumen 116 prevents the guidewire 70 fromabraiding or rupturing the expandable body 68.

As shown in FIG. 37, the distal end of the expandable body 64 includes aguide assembly 133. In the illustrated embodiment, the guide assembly133 comprises a two piece construction, having an inner sheath 132 andan outer sheath 134.

As shown in FIG. 37, the inner sheath 132 is an elongated member havinga proximal region 136 and a distal region 138. In a representativeembodiment, the inner sheath 132 is approximately 1.0 inch to 2.5 incheslong (in a most preferred embodiment, it is about 1.75 inches long). Agroove 140 (see also FIG. 38) formed in the wall of the inner sheath 132extends in the proximal and distal regions 136 and 138 and serves toreceive the guidewire lumen 116.

As FIG. 37 shows, the distal region 138 is generally round with radiallyextending vanes 142. In a representative embodiment, the distal region138 is approximately 1.25 inches long (and the corresponding proximalregion 136 being about 0.440 inch long). As illustrated in FIG. 39, thearea between the vanes 142 serves to receive the distal end of thespines 66. In the embodiment illustrated in FIG. 38, there are threevanes 142. Of course, a greater or lesser number of vanes 142 may beutilized to accommodate a desired number of spines 66. As shown in FIG.39, the spines 66 are, e.g., adhesively attached to the inner sheath 132between the vanes 142.

To aid in stability of the overall assembly and support for theexpandable structure 64, the inner sheath 132 is desirably made of arelatively stiff material, having a durometer of, e.g., about 95 A.

As seen in FIG. 38, an opening 144 in the proximal region 136 isprovided. As illustrated in FIG. 39, the opening 144 serves to couplethe distal end of the expandable body 68 to the inner sheath 132.

The distal region 138 of the inner sheath 132 extends in a taper fromthe proximal region 136. In this arrangement, the distal end of thedistal region 138 is approximately even with distal end of the guidewirelumen 116. The guidewire lumen 116, carried by one of the spines 66, islocated within the groove 140 and is also, e.g., adhesively attached tothe inner sheath 132 along the length of the groove 140.

As FIG. 37 shows, the outer sheath 134 is a hollow, elongated, taperedmember adapted, in the illustrated embodiment, to fit over the innersheath 132. When positioned over the inner sheath 132, the outer sheath134 extends distally a desired distance beyond the inner sheath 132. Ina representative embodiment, the outer sheath 134 is approximately 1.5inches to 3.5 inches inches long (in a most preferred embodiment, it isabout 2.75 inches long). The distal end of the outer sheath 134 includesan opening 146 accommodating passage of a guidewire 70.

The outer sheath 134 is desirably made of a material less stiff than thematerial selected for the inner sheath 132, e.g., having a durometer of,e.g., about 60 A. The reduced stiffness provides minimal discomfort tothe patient.

The selection of a relatively stiff material to support the distal endof the expandable structure 64 and of a less stiff material at thedistal end of the guide assembly 113 to provide minimal discomfort tothe patient, results in a gradient of decreasing stiffness from theproximal end of the guide assembly 113 to the distal end of the guideassembly 113. This maximizes both stability of the assembly and patientcomfort.

The inner sheath 132 and outer sheath 134 can be formed by conventionalmolding techniques. Suitable materials for both the inner and outersheaths 132 and 134 include Kraton™ and Santoprene™.

Alternately, the inner and outer sheaths 132 and 134 may be molded as aunitary piece utilizing an overmolding process. In this embodiment, theovermolding process permits the manufacture of a single piece having ablended durometer. Thus, a stiffness gradient as previously describedcan be achieved in a single molded piece.

In use, the patient lies awake in a reclined or semi-reclined position.A bite block 10, desirably carrying a gripping tool (T) as previouslydescribed is placed in the patient's mouth and properly positioned (see,e.g., FIG. 17).

In this embodiment, the gripping tool (T) is an embodiment in which thejaw assembly 18 is eccentrically located within the bite block opening11 (see embodiments T6-T8). The physician passes a small diameterguidewire 70 through the patient's mouth and pharynx, and into theesophagus 84 to the targeted site, as previously described (see FIG.18). An endoscope can be deployed as previously described (see FIG. 19).

Upon removal of the endoscope, the physician threads the guidewire 70(see FIGS. 33 and 40) by insertion through the distal opening 146 in theguide assembly 133. The guidewire 70 is advanced into the guidewirelumen 116 of the spine and exits through the proximal opening 130resting on the exterior surface of the catheter tube 19.

As shown in FIG. 12, the catheter 58 is inserted through the opening 11in the bite block 10 alongside the jaw assembly 18. The expandablestructure 64 is advanced along the guidewire 70 through the patient'smouth and pharynx and to the desired position in the esophagus 84, e.g.,lower esophageal sphincter 90. The positioning of the expandablestructure 64 in the lower esophageal sphincter 90 is illustrated inFIGS. 21 a and 21 b.

As seen in FIG. 13, the catheter tube 19 is then moved laterally toposition it within the gripping tool (T6, T7, or T8) and the cathetertube 19 is positioned within the gripping tool (T6, T7, or T8), aspreviously described (see FIGS. 12 and 13).

An ablation sequence as previously described is then performed (see,e.g, FIGS. 27 a and 27 b). Multiple ablation sequences can be performedto create a desired lesion, as previously described (see e.g., FIG. 29).The jaws of the gripping tool are opened each time the catheter tube 19is repositioned for a new lesion set. Of course, procedures other thanablation may be performed.

Upon completion of all desired procedures, the physician assures thatthe electrodes 60 are retracted and the expandable body 68 is contracted(e.g., air or water is withdrawn from the balloon by a syringe through aport on the handle 62 of the catheter 58) (not shown).

The elements 17 of the gripping tool (T) are then verified as being inthe open position, the catheter 58 and guidewire 70 are withdrawn, andthe bite block 10 is removed from the patient's mouth.

While the embodiment just described details the use of the guidewirelumen 116 located within the tubular spines 66 in combination with agripping tool (T) having an eccentric jaw assembly 18 (see embodimentsT6-T8), it is to be understood that this embodiment of the guidewirelumen 116 is also adapted for use with a gripping tool (T) having acentrally located jaw assembly 18 (see embodiments T1-T5).

Features and advantages of the invention are set forth in the followingclaim.

1. An assembly for treating a tissue region comprising a catheter tubehaving a distal end, an expandable structure projecting beyond thedistal end of the catheter tube and including a far end; and a distaltail projecting beyond the far end of the basket assembly, the distaltail including a guidewire lumen that accommodates passage of aguidewire without threading the guidewire through the catheter tube.